Thankyou sir, much appreciated. do you have any "D"type cells that I could put in this battery pack to at least get it going for a bit?
If/when I get the car I plan to repower it with lithium anyway so the original pack would no longer be needed.... is this correct, or does the lithium pack piggy back onto the original pack similar to the later Prius plug in hybrid mod kits?

T1 Terry

Last edited by T1 Terry on Sat, 15 Nov 2014, 09:05, edited 1 time in total.

Hi Terry,
What you do is flatten all the old cells one cell at a time, discharge at maybe 5A until the cell voltage is o.8V, then disconnect the load and do the next. The cells should recover to above 1.1V after standing for a few hours. Any cells that are below 1.1V to start with are probably suspect, but as long as they are not short you will be able to drive the car. charge these a bit first maybe 1 Ah, then do the discharge, same as the others. Change any individual cells that don't bounce back after a discharge. Also check the MAF sensor, often this is the real problem. see https://groups.yahoo.com/neo/groups/Mk1_Prius/files and "how to clean a Maf sensor".
When you have done the whole pack like this the car should start and charge the pack.If you do this it should be ok for a while before you get another turtle, though you will get a few immediatly after doing this. when It starts giving more that 1 turtle a trip run the car backwards and if you have to go forwards do it smartly, don't let it charge, until you get a turtle, then carry on until the car stops going backwards. turn off and re do the battery, but any cells that are below 1.2 volts must be changed.
Replacement cells come out of another pack that has been thrown out, old pack should be charged and left standing for a few months, any cells that are above 1.27 or so can be used.

T1 Terry wrote:do you have any "D"type cells that I could put in this battery pack to at least get it going for a bit?
If/when I get the car I plan to repower it with lithium anyway so the original pack would no longer be needed....

I have heaps - problem is they're all nearly 20 years old, so won't be particularly reliable

I'm happy to send over as many sticks as you like -- I have around 120

plan with the lithium pack is to replace the original battery - but this is still in a very much prototype stage, I wouldn't bank on it being available in the near future.

In other news - today I was given another prius

my latest revelation is that there are several different versions of the Battery ECU that originally came with the NHW10

I'm hoping the differences are all software, but it has prodded me more in the direction of trying to get the battery ECU program modified rather than trying to come up with a work around that works reliabley with all battery ECU versions

gtyler54 wrote: Hi Terry,
What you do is flatten all the old cells one cell at a time, discharge at maybe 5A until the cell voltage is o.8V, then disconnect the load and do the next. The cells should recover to above 1.1V after standing for a few hours. Any cells that are below 1.1V to start with are probably suspect, but as long as they are not short you will be able to drive the car. charge these a bit first maybe 1 Ah, then do the discharge, same as the others. Change any individual cells that don't bounce back after a discharge. Also check the MAF sensor, often this is the real problem. see https://groups.yahoo.com/neo/groups/Mk1_Prius/files and "how to clean a Maf sensor".
When you have done the whole pack like this the car should start and charge the pack.If you do this it should be ok for a while before you get another turtle, though you will get a few immediatly after doing this. when It starts giving more that 1 turtle a trip run the car backwards and if you have to go forwards do it smartly, don't let it charge, until you get a turtle, then carry on until the car stops going backwards. turn off and re do the battery, but any cells that are below 1.2 volts must be changed.
Replacement cells come out of another pack that has been thrown out, old pack should be charged and left standing for a few months, any cells that are above 1.27 or so can be used.

Thanks for the info and the links, I can't seem to get the Yahoo groups one up but I found a few other forums with similar information regarding the MAF sensor and as an ex motor mechanic I should be able to fault find the eng problems if it has any, the rest of the ECU stuff that controls the battery pack and electric motors is another story entirely
I doubt the seller will allow me to take the battery pack home to play with it so it might be one of those fingers crossed and hope for the best type purchases.
The other possible is an ex taxi in the Brisbane area, 2008 model but with 600,000kms on the clock it's been around a bit and around 4 times the price by the time I fly up there to drive it home.

T1 Terry wrote:do you have any "D"type cells that I could put in this battery pack to at least get it going for a bit?
If/when I get the car I plan to repower it with lithium anyway so the original pack would no longer be needed....

I have heaps - problem is they're all nearly 20 years old, so won't be particularly reliable

I'm happy to send over as many sticks as you like -- I have around 120

plan with the lithium pack is to replace the original battery - but this is still in a very much prototype stage, I wouldn't bank on it being available in the near future.

In other news - today I was given another prius

my latest revelation is that there are several different versions of the Battery ECU that originally came with the NHW10

I'm hoping the differences are all software, but it has prodded me more in the direction of trying to get the battery ECU program modified rather than trying to come up with a work around that works reliabley with all battery ECU versions

This NWH10 is sounding more like the go if I can get some s/h cells to put into it to at least get it to run. If there are 40 cells in pack, is there an average number that will have been reverse charged and killed? Or is it a bit of lottery thing, ya buys ya ticket and takes ya chances

T1 Terry
EDIT: How do you manage to get them given to you? Are you willing to share that secret

Last edited by T1 Terry on Sat, 15 Nov 2014, 17:46, edited 1 time in total.

How many bad cells will a car have? Actually, often there will be none that will stop you driving it. It depends on how the pack has been treated. If, when a battery is failing, the car is driven into the ground most of the cells can be leaking electrolyte.
What happens is this;
1) car starts having turtles.
2) because Toyota won't service them the owner keeps on using it after
the fault warning triangle appears.
3) every time a car has a turtle the ECU SOC counter is reset to zero (shown by the MFD indicating 20% orange bar in the battery symbol), even when it has just charged the battery a minute ago.
4) car now charges the pack to full. (pack is actually full to start with, maybe only 1 empty cell that caused the turtle.) and all the good cells overheat because they have been overcharged, energy has nowhere to go.
5) hot cells cause the thermistors to change resistance, battery ECU disconnects the battery but engine still runs, car will not go.
6) Driver learns that restarting the car now lets him drive it again.so this carries on, pack is wrecked from overheating.

If the driver is more careful then he stops driving it at the first triangle. If you get the car at this stage and you may just equalize the charge on the cells and drive it for a month or so until you get another turtle. If you do the same it will go for another month.
If you have a scanner and you find which cell is causing the problem and change that each time the car will improve every time you change one. our first car that we bought with a faulty pack in 2007 is still going fine on the old pack.

yes, basically senses total pack voltage (seems to stop pack discharge at 240V), any cell below 1V and keeps track of the state of charge from the current in/out. I think it may also stop charging at about 380V, but that will only happen on a equalization charge initiated from the scanner

T1 Terry wrote: What will that cost to get back over here? It's costing me around the $700 mark to get this 2008 Prius just from Brisbane to here so it can't be cheap getting one over from New Zealand.

T1 Terry wrote: What will that cost to get back over here? It's costing me around the $700 mark to get this 2008 Prius just from Brisbane to here so it can't be cheap getting one over from New Zealand.

T1 Terry

look at where he is under his name

Location: Hamilton NZ

Ummm..... Had a look on Google maps and it's closer than from here to Sydney

I think that may be the same guy who rang me regarding my ad on Gumtree looking for a project NWH10. He was really only after information so I guided him here to the forum. I can probably pick that one up in Sydney for $1000 but I've since bought a 2008 model ex taxi from the sunshine coast for $2,600 delivered to the door so I'm not sure I'd get away with another project car in the front yard Well, not until I get this one going and the wife driving it anyway

It doesn't seem to matter how long the car bakes in the sun for, I haven't seen the batteries start a trip above 30 deg C all summer

however, while driving (and actively discharging the battery at between 20 and 35A continuous) the battery slowly heats up to 40 deg C.
at this point the car begins reducing the max regen current limit which is a shame.
it gets reduced to 0 at around 46 deg C

I haven't seen the battery go above 48 deg C

the ~18 deg C temp rise from driving around is something I suspect I won't be seeing in the A123 cells